Refrigerating system



June 21, 1932. 1 G, K|NG 1,863,750

REFRIGERATING SYSTEM Filed July 9, 1925 Patented `lune 21, 1932 UNITED STATES PATENT OFFICE JESSE G. KING, OF DAYTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, lTO FRIGIDAIRE CORPORATION, A CORPORATION 0F DELAWARE f REFRIGERATING SYSTEIYI' Application filed July 9, 1925. Serial No. 42,564.

The present invention relates to refrigerating systems and particularly to that type of system in which a plurality of refrigerating chambers are cooled to relatively different temperatures as for example, a chamber for maintaining ice cream or the like, at a relatively low temperature, and a chamber for cooling beverages without freezing them.

One of the objects of the present invention is to simplify the construction of such a system thereby to reduce the cost and facilitate the manufacture thereof. One manner of carrying out the above object is to provide one cooling unit and one mechanism for circulating refrigerant medium. The cooling vunit is located in one of the chambers and a conduit extends from the cooling unit into the other chamber.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred' form of embodiment of the present intion is clearly shown,

In the drawing:

Fig. l is a diagrammatic view of the im proved refri erating system showing the cooling chambers in section,

Fig. 2 is a top plan view of the cooling unit of the system, and l Fig. 3 is a section taken longitudinally through the header shown in Fig. 2, said section showing the mechanism for controlling the flow of refrigerant.

Referring to the drawing, for illustrative purposes there is shown a cabinet for ice cream or the like. and a cabinet 21 for cooling Vwater and other beverages. The ice cream cabinet contains a heat transfer medium 23,

- such as brine, which will not freeze at waterfreezing temperaturein which a container -24 is immersed for receiving the material to be maintained frozen. The present invention may use an evaporator 25 of the type in which the admission of refrigerant is controlled by a float valve 25a which opens and' closes in accordance vwith the quantity of refrigerant in the header 26 of the evaporator. Refrigerant is conducted to the header through 'a pipe 28 and vaporized refrigerant is drawn from the header through a pipe 29. plurality of pipes 30 are connected with the header 26 in4 parallel relation with respect to one another.r These pipes 30 always contain a quantity of refrigerant and the header 26 and pipes 30 are surrounded by the medi-V um 23 in the cabinet for cooling said medium.

Cabinet 21 contains a heat transfer medi` um 32, preferably Water,I which surrounds coils-.containing drinkingwater, carbonated water or the like, one of which is shown at 33.' One'or more conduits 34 are immersed inthe medium 32 and each is connected witlithe header 26 by pipes 36 and 37 and couplings 38and 39. Since the'couplings are located outside the cabinet 2l, an evaporator structure having no joints or connections what'- ever within the cabinet 2l is provided. `This is advantageous where` it is imperative-that .no refrigerant escape into the cabinet or no air, water or other foreign substance enter the refrigerating system. Since leaks almost invariably occur at joints or connections, tlie 5 entire source of leaks is removed from the cabinet. If the cabinets are spaced from one another, as shown, insulation 40 is placed around the pipe portion between the cabinets.

The means -herein shown for withdrawing refrigerant from the evaporator 25 and conduit 34, and for condensing the refrigerant and for forcing the same into the evaporator and said conduit, includes a compressor 42 connected at its suction or low-pressure side with pipe 29. The vaporized refrigerant is Withdrawn from the evaporator 25 through the pipe 29 and compressed and forced into a. condenser 43 whence it is conducted by pipe 28 to the header 26.

A suliicient number of pipes 30 are connected with the header 26 to maintain the. temperature of the solution 23 at a certain low point'and the number of conduits 34 required within the cabinet`21 is computed in accordance with the size of said cabinet and the required temperature` of the medium 32. A suiicient number of conduits 34 are provided to maintain a quantity of ice 45 around said conduits, but sufficient to freeze only a portion of the medium 32. ln this manner the ice will maintain the rest of the medium 'nsy `32 substantially at but slightly above waterfreezing temperature. The coil 33 is vspaced a substantial distance from the conduits 34,

duit 34 becomes less effective as ice forms thereabout, therefore, it is not necessary that the size or number of conduits be accurately computed. If, for example, slightly more heat transfer surface of conduits 34 is exposed to the medium 32 than is necessary for maintaining the desired low'temperature for adequately cooling the coil 33, the ice 45 forming on said conduits 34 will function as insulation to prevent the cooling of the medium 32 to such a degree as to freeze the liquid within coil 33.

The compressor 42 is herein driven by a motor 45 through a belt 46.` The circuit tov the motor is controlled by a snap switch 47 which is actuated 'through a lever 4S by a metal bellows 49 adapted to expand and contract in accordance with the pressure therein. This bellows 49 is connected with the pipe 29 in the low-pressure side of the refrigerating system and therefore responsive to the pressure Within the evaporator 25 and the conduits 34. y

T he temperature of the refrigerant within the evaporator 25 and in the conduit or conduits 34 is substantially equal and the ice surrounding conduit 34 functions as an insulation for said conduit so that the refrigerant therein is not directly subjected to the `relatively high temperature of medium 32. When the temperature of solution 23 has increased to a certain de ee the pressure within the evaporator 25 will cause the bellows to expand to close the motor circuit to operate the compressor. Likewise the rise in tem perature of medium 32 in cabinet 2l will cause some of the ice 45 to melt and increase the heat transfer between the medium and the conduit 34 whereby the temperature of the refrigerant in conduit 34 is increased. Due to the increase in temperature of the refrigerant in conduit 34, the teu'iperature of refrigerant in evaporator 25 will rise and thereby cause the compressor to bc operated. Therefore it is apparent that the compressor is responsive to the condition within the cabinet 2l as well as conditions in the cabinet 20.

I The switch and bellows are constructed to interrupt the motor circuit when the pressure within the low pressure side has been reduced to such a degree thatthe solutions 29 lnd 32 are reduced to a certain low temperaure.

While the form of embodiment ofthe present 1nvcnt1on as herein disclosed constitutes a preferred form, 1t 1s to be understood that other forms-might be adopted, all coming within the scope ofthe claims which follow.

lVhat is claimed is as follows:

1. Refrigerating apparatus comprisin in.

combination a pair of chambers to be coo ed,

an evaporator forming a reservoir for liquidv cluding a conduit having both its ends connected with the evaporator 'and arranged to receive refrigerant therefrom, and means for automatically maintaining the frigerant at a predetermined level both in the evaporator and the conduit.

2. Refrigerating a paratus com risin in combination a pair of) chambers to e coo ed, an evaporator forming a reservoir for liquid refrigerant having heat exchange means disposed in one of the chambers, means for circulating refrigerant through the evaporator, means for cooling` the other chamber including a conduit having-both its'ends connected with the evaporator and a single means for automatically maintaining the hquid refrigerant at a predetermined level both in the evaporator and in the conduit.

3. Refrigerating apparatus comprising in combination a plurality of chambers to be cooled, an evaporator forming a reservoir for liquid refrigerant and having heat exchange means disposed in one of the chambers, a refrigerant conduit in the other chamber and having both its ends connected with the evaporator, the evaporator and conduit being arranged and constructed to maintain the chambers at different temperatures, means for supplying liquid refrigerant to the evaporator and means within the evaporator for automatically maintaining the li uid refrigerant at a predetermined level oth in the evaporator and the conduit.

4. Refrigerating apparatus comprising in combination a plurality of 4chambers to be cooled, an evaporator forming a reservoir for liquid refrigerant and having heat exchange meansv disposed in one of the chambers, a refrigerant conduit in the other chamber and having both its ends connected with the evaporator, the evaporator and conduit being arranged and constructed to maintain the chambers at diiferent temperatures, means for supplying liquid refrigerant to the evaporator and a single means for automaticallvmaintaining the liquid refrigerant at a prec eter-mined level both in the evaporator and'n theconduit.

In testimony whereof I hereto affix my signature.

JESSE G. KING.

liquid re-l 

